One of the key tenets of database system design is making efficient use of storage and memory resources. However, existing database system implementations are actually extremely wasteful of such resources; for example, most systems leave a great deal of empty space in tuples, index pages, and data pages, and spend many CPU cycles reading cold records from disk that are never used. In this paper...

Article history: Received 8 July 2015 Received in revised form 26 July 2015 Accepted 29 July 2015 tion to the era of factory-scale analysis. The great acceleration of progress we've seen in other fields is now coming to healthcare. At Google, we have more than 15 years of experience with finding the value in information. We have built tools to organize information and make it accessible and use...

The basic unit of information in a computer is the bit; it is simply a quantity that takes one of two values, 0 or 1. A sequence of k bits is a k-bit word. Words have no intrinsic meaning beyond the value of the bits. We can assign meaning to words by interpreting them in various ways. Depending on the context we impose, a word can be viewed as an integer, as a boolean value, as a floating poin...

This reprint is provided for personal and noncommercial use. For any other use, please send a request Brian Hayes by electronic mail to [email protected].

1 Random Bit Generators 2 1.1 Pseudo-Random Bit Generators . . . . . . . . . . . . . . . . . . . . 2 2 Physical Sources for Random Bits 3 2.1 Exploiting Air Turbulence in Hard Disk Drives . . . . . . . . . . 3 2.2 Generating Unbiased Random Bits . . . . . . . . . . . . . . . . . . 4 3 Generating Random Seeds 5 3.1 Obtaining Random Timings . . . . . . . . . . . . . . . . . . . . . . 6 3.2 Locati...

Cellular Automata are discrete physics-like systems that can be exactly simulated by digital hardware. These systems can incorporate many realistic physical constraints and still be capable of performing digital computation. Such systems bridge the boundary between physical models and computational models, and so can play a central role in investigating the relevance of physical ideas to the th...

Consider the following simple communication channel model: an error-free bit pipe leading to a buffer modeled by a single-server queue whose “packets” or “customers” are single bits. If the service rate is p bits/sec, common wisdom would indicate that the Shannon capacity of this communication link is p bits/sec. As we show in this paper, that intuition is wrong: the answer is actually higher t...

* Dept. of Economics and Policy Studies, 400 Decio Hall, University of Notre Dame, and Visiting Scholar, International Center for Advanced Studies, New York University. Please direct all correspondence to [email protected]. I should like to thank the audiences at CarnegieMellon, University of Stirling and the Universidad Republica de Montevideo, Uruguay, and more particularly, Matthias Klaes, D...

This article considers novel methods for evolving species in a standard generational evolutionary algorithm. Unlike other methods, these methods replace the concept of distance between individuals with tag bits that identify the species to which an individual belongs.